Are these caps autoclavable/safe for yeast freezing

[wfowlks]

Hello,

So I recently purchased some vials from ebay for the purpose of yeast harvesting and freezing. I just got the vials and noticed that inside the cap there is like a seal that looks like a thick piece of paper that was laminated. I was wondering if anyone knew if these would be ok for wet/yeast storage. Or if I should go after different caps.

 

[Wolfbrau]

Looks OK, roughly. If it looks like crap after autoclaving? Do not use.

Alternative: Use a simple boil. I'm comfortable with that, as long as I step up sufficiently.